I had an SL8-5 and it was a good rifle. I got rid of it for a number of reasons.
First, I didn't like the ergos of the stock - the thumbhole really bit into the webbing on my hand and I didn't like the general feel after longer periods of shooting. I probably could have changed the stock but I really didn't like the idea of spending more money on an already high ticket item for something that was in my mind pretty basic.
Second, I didn't like the weight distribution of the rifle. I like polymer firearms (i.e. Glock, HK, Walther) but I felt that the SL8 was too front heavy and it didn't balance right. I had decided that I like aluminum better (AR family) and have bought a varminter AR to replace the SL8.
Third, I found that as a non restricted - it really didn't fit into my battery that well. I like lighter weight rifles for hunting and the SL8 wasn't as ergo for plain range shooting. So I decided to get a good boltgun for hunting (cheaper) and stick with ARs for range shooting. As well, aftermarket parts are a premium for the SL8 and things I wasn't too fond of were polymer sight rails/sights and limited avail of spare parts/accessories.
Things I liked about the SL8. The twist of the barrel is better for long range shooting then say the PE90 (7" vs 10") and the price isn't too bad for a non restricted black rifle. It was accurate (I like the chrome lined heavy bbl). Accuracy was pretty good for a semi.
George: to remove the locking pin for the handguard is simple. Pop the pin out and pull the handguard straight off...